Metallization structure on a fluorine-containing dielectric and a method for fabrication thereof

ABSTRACT

The present invention is related to a metallization structure on a fluorine-containing dielectric. This metallization structure includes a conductive pattern; a fluorine-containing dielectric; and a barrier layer containing a material, i.e. a near noble metal such as Co, Ni, Pt, and Pd. The barrier layer includes at least a first part, being positioned between the fluorine-containing dielectric and the conductive pattern, the first part containing at least a first and a second sub-layer, the first sub-layer contacting the fluorine-containing dielectric being impermeable for fluorine.

This application is a continuation of Ser. No. 09/237,876 filed Jan. 27,1999 now U.S. Pat. No. 6,323,555, which claims the benefit of U.S.Provisional Application No. 60/072,895, filed on Jan. 28, 1998.

FIELD OF THE INVENTION

The present invention is related to a new metallization structure beingpart of a structure used to interconnect electronic components ordevices. Such components or devices can be part of an integratedcircuit. Particularly, a multi-level Cu-containing metallizationstructure is disclosed based on fluorine-containing dielectrics.

BACKGROUND OF THE INVENTION

The ongoing miniaturization in integrated circuits with increasedcomplexity and multilevel metal layers and the focus on increasing speedof these circuits demand for low permittivity materials, particularlyfor use as intermetal dielectric layers. Conventionally, metalinterconnects, mostly aluminum layers, with silicon dioxide asintermetal dielectric are used, but this conventional solution will notbe able to meet the stringent specifications resulting from the abovementioned trends. Therefore, to avoid that the larger portion of thetotal circuit delay is caused by the resistance and capacitance of theinterconnect system, one has to reduce the permittivity of thedielectric used. This is stated in numerous publications, e.g. in Table1 of R. K. Laxman, “Low ε dielectric: CVD Fluorinated Silicon Dioxides”,Semiconductor International, May 1995, pp. 71-74. Thereforeminiaturization has lead to an intensified search for new low Kmaterials. A low ε material, a low K material and a material with a lowpermittivity are all alternative expressions for a material with a lowdielectric constant, at least for the purposes of this disclosure. Themost desirable material should have a low K value, low mechanicalstress, high thermal stability and low moisture absorption. Furthermore,the desired material should be selected based on the compatibility withstate-of-the-art semiconductor processing steps and tools.

Part of the search for new low K materials was directed to changing theproperties of silicon dioxide as deposited. Deposited silicon dioxide isthe most widely used intermetal dielectric material having a K value ofabout 3.9. Several publications have indicated that the K value ofsilicon dioxide films can be reduced by introducing increasing amountsof fluorine in said films. Fluorine is the most electronegative and theleast polarizable element on the periodic table. Incorporation offluorine reduces the number of polarizable Si-OH bonds and alsoinfluences the silicon oxide such that it has a less polarizablegeometry to thereby lowering the K value of the fluorinated siliconoxide films. A wide variety of processes to deposit fluorinated siliconoxide films are known like e.g. a Plasma Enhanced Chemical VapourDeposition (PECVD) process as in the U.S. Pat. No. 5,641,581. Usingthese processes K values in the range between 3 and 3.5 are reporteddependent on the amount of fluorine atoms incorporated, i.e. anincreasing amount of fluorine leads to a decrease of the K value.

Besides the focus on changing the properties of silicon oxide, there isan ongoing search for new low K materials. Among these new materials arethe organic spin-on materials, having a K value in the range from 2.5 to3, and the inorganic low-K materials as e.g. xerogels having a K valuetypically lower than 1.5. Many of these new low-K materials comprisefluorine. The organic materials are of particular interest because theyfeature simplified processing, excellent gap-fill and planarization.Furthermore the K-value of organic materials, which comprise Phenylgroups, can be additionally lowered by plasma fluorination as e.g. in H.Kudo et al., Mat. Res. Symp. Proc., Vol. 381, pp. 105-110, 1985. Bydoing so the K-values can be lowered yielding a range from 2 to 2.5instead of from 2.5 to 3.

In summary, it is clear that fluorine-containing dielectrics have ingeneral a lower K-value than there unfluorinated counterparts. Thisholds both for polymer like and ceramic like dielectrics. Thereforefluorine-containing dielectrics are of particular interest in order toavoid that the larger portion of the total circuit delay is caused bythe capacitance of the interconnect system. Despite all these advantagesfluorine-containing dielectrics are not compatible with currentmetallization structures using metallization materials such as Ti, orTa, or W, or the nitrides of each of the aforementioned materials, orCu, or Al. This is due to the fact that the incorporation of fluorinehas been shown to be detrimental for the aforementioned metallizationmaterials.

AIMS OF THE INVENTION

It is an aim of the present invention to provide a metallizationstructure which is compatible with fluorine-containing dielectrics.Therefore, a layer has to be provided which is at least conductive andsubstantially impermeable for fluorine, i.e. forms a diffusion barrierfor fluorine. Preferably, this layer has a low contact resistance to asilicon layer or silicon substrate. In case this metallization structurecomprises Cu, a layer has to be provided which is substantiallyimpermeable for Cu.

It is a further aim of the invention to provide a metallizationstructure being compatible with fluorine-containing dielectrics andcomprising a layer which is at least conductive, impermeable forfluorine and impermeable for Cu. Even more preferably, this layer has alow contact resistance to a silicon layer or silicon substrate.

SUMMARY OF THE INVENTION

In an aspect of the invention a metallization structure is disclosedcomprising a barrier layer, said barrier layer being formed on theexposed parts, i.e. the uncovered parts, of a fluorine-containingdielectric. This barrier layer should adhere well on saidfluorine-containing dielectric. This barrier layer should also neithercorrode nor reveal a deterioration of its characteristics by theexposure to a fluorine. Furthermore, this barrier layer should also forma diffusion barrier for fluorine, by forming stable non-volatilefluorides, in order to inhibit the corrosion of other parts of themetallization structure. According to this aspect of the invention, ametallization structure is disclosed comprising:

a conductive pattern;

a fluorine-containing dielectric; and

a barrier layer comprising at least a first part, being positionedbetween said fluorine-containing dielectric and said conductive pattern,said first part consisting of a first sub-layer of a conductive materialand a second sub-layer of a fluoride of said conductive materialadjacent to said fluorine-containing dielectric. Particularly both theconductive pattern and the fluorine-containing dielectric can becompletely encapsulated by the barrier layer.

In an embodiment of the invention, a metallization structure isdisclosed comprising a barrier layer of a near noble metal which is atleast highly impermeable for fluorine and preferably impermeable for Cu.Preferably the near noble metal Co is use which forms a barrier layerwhich is both substantially impermeable for fluorine and for Cu. Co ismuch less reactive than the refractory metals. Co adheres well onfluorine-containing silicon oxide based materials as well as onfluorine-containing organic polymers. Moreover, in contact with asilicon substrate Co can form a silicide-cobalt having a low resistivityand a low contact resistance to a silicon substrate. For the purposes ofthis disclosure, a silicide-cobalt is defined as Co_(x)Si_(y), x and ybeing positive numbers. Moreover, the fluorides of Co are stable andnon-volatile, i.e. contrary to e.g. Ti. Furthermore, it has beenrevealed that Co reacts readily with fluorine thereby forming an in-situcobalt-fluoride layer, i.e. a layer of Co_(x)F_(y), x and y beingpositive numbers. The growth of this cobalt-fluoride layer is selflimiting resulting in a maximum thickness of the layer of about 5 nm.The thickness of this layer is typically 3 to 4 nm. Consequently,contrary to e.g. Ti which is permeable for fluorine, by the reaction ofCo or another near noble metal, such as Ni, Pd or Pt, with afluorine-containing dielectric a layer of a fluoride of this near noblemetal is formed. This layer inhibits the out-diffusion of fluorine fromsaid fluorine-containing dielectric and thereby avoids the exposure ofother parts of the metallization structure to fluorine.

In another embodiment of the invention, a metallization structure isdisclosed where the conductive pattern is composed of at least one metalselected from a group comprising Al, Cu, an Al-alloy and a Cu-alloy.Particularly, a Cu-containing metals is selected. This metallizationstructure can further comprise a barrier layer, impermeable for copper,being positioned between said conductive pattern and said contactbarrier layer. Preferably, this barrier layer is a Ta layer or acompound thereof.

In another embodiment of the invention, a metallization structure isdisclosed, further comprising a second part of said barrier layer ofsaid conductive material, being positioned between silicon layer andsaid conductive pattern and wherein said second part is in contact withsaid silicon layer. Particularly, the silicon layer can be at least apart of a silicon wafer. This second part of said barrier layercomprises a first sub-layer of said conductive material, e.g. Co oranother near noble material, and a second sublayer of a silicide of saidconductive material, e.g. a silicide-cobalt, said second sub-layercontacting said silicon layer. This second sub-layer provides a lowohmic contact to the exposed parts of the silicon layer.

In another aspect of the invention, a method for fabricating ametallization structure on a substrate is disclosed, comprising thesteps of:

depositing a layer of a conductive material on at least one exposedsurface of a fluorine-containing dielectric formed on said substrate;

allowing the reaction between said layer of said conductive material andsaid fluorine-containing dielectric to thereby form a layer of afluoride of said conductive material at the interface between said layerof said conductive material and said fluorine-containing dielectric; and

depositing at least one metal on said layer of said conductive material.depositing a contact barrier layer on a patterned fluorine-containingdielectric layer thereby creating a diffusion barrier for fluorine; and

forming a conductive pattern on said first contact barrier.

In a further embodiment of the present invention the reaction betweenthe layer of the conductive material, i.e. the barrier layer, and thefluorine-containing dielectric is stimulated by heating the substrate.Particularly, this heating can be performed at a temperature betweenroom temperature and 500 degrees C., or between 50 degrees C. and 500degrees C., or between 50 degrees C. and 300 degrees C.

In another embodiment of the invention, a method is disclosed tofabricate a metallization structure, wherein prior to the formation ofthe conductive pattern, preferably composed of Cu or a Cu-alloy, anadditional layer, impermeable for Cu, is deposited on the barrier layerof the near noble metal. Preferably, this additional layer is a layercomprising Ta or a compound thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a schematic process-flow used to fabricate a particularmetallization structure, i.e. a dual-damascene structure, according toan embodiment of the invention.

FIG. 2 depicts XPS (X-ray Photo-electron Spectroscopy) spectra of somesamples which are configured as follows:

A Co layer with a thickness of 10 nm is deposited by means of a physicalvapor deposition technique on an in-situ fluorinated FLARE™ II layer.The thickness of the FLARE™ II layer is 600 nm. Prior to the Codeposition the FLARE™ II layer is in-situ fluorinated by exposure in achamber of a plasma tool to an ambient comprising NF₃. The pressure inthe chamber was 1.3 Torr will the ambient temperature was 80 degrees C.

The FLARE™ II layer was deposited on a silicon wafer with a silicondioxide layer thereon.

After the Co deposition, some samples (21) were heated during 10 minutesat 350 degrees C., while some samples (20) were not subjected to a heattreatment. Next, samples are given for XPS analysis. The analysis isperformed at the interface layer between the Co and the fluorinatedFLARE™ II layer.

FIG. 2a) depicts the F 1s peak.

FIG. 2b) depicts the Co 2p peak.

Remark that the intensity scale in both pictures may only be used todetermine relative intensities.

Both samples have a very intense F peak. In addition, the Co2p peak ofboth samples has a clear high binding energy structure (˜783 eV) whichcan be related to the low binding energy peak of the F1s peak andattributed to a fluoride of Co. The high binding energy peak of the F1speak is attributed to C-F bounds, where the C originates from the FLARE™II layer.

When comparing the spectra of the samples with (21) or without heattreatment (20), from the F1s spectra, it can be concluded that thefluoride intensities are significantly higher than the C-F intensities.This indicates a stronger reaction due to the heat treatment.

DETAILED DESCRIPTION OF THE INVENTION

In relation to the appended drawings the present invention is describedin detail in the sequel. It is apparent however that a person skilled inthe art can imagine several other equivalent embodiments or other waysof executing the present invention, the spirit and scope of the presentinvention being limited only by the terms of the appended claims.

The introduction of fluorine-containing dielectrics in modern and futuresemiconductor processes requests a metallization structure which iscompatible with said fluorine-containing dielectrics. Thisfluorine-containing dielectric can be a polymer like or ceramic likedielectric, e.g. a fluorinated silicon oxide. Alternatively thisfluorine-containing dielectric can also be a dielectric where thefluorine is introduced only after the deposition, for instance by plasmafluorination. This holds especially for organic polymers comprisingunsaturated carbon bonds such as phenyl groups. Examples of organicpolymers comprising phenyl groups are the benzocyclobutarenes, i.e.benzocyclobutene (BCB) commercially available as Cyclotene 5021™, polyarylene ether, i.e FLARE™ II, aromatic hydrocarbon, i.e. SILK™,polyimides. An advantage of introducing fluorine after the deposition isthat this fluorination can be performed locally. Thisfluorine-containing dielectric is formed on a substrate. The substratecan be a partly processed or a pristine wafer or slice of asemi-conductive material, like Si or Ga As or Ge, or an insulatingmaterial, e.g. a glass slice, or a conductive material. Said substratecan comprise a patterned conductive layer. Particularly, in case saidsubstrate is a partly processed wafer or slice; at least a part of theactive and/or passive devices can already be formed and/or at least apart of the structures interconnecting these devices can be formed.

In order to be compatible with a fluorine-containing dielectric ametallization structure has to be configured comprising a barrier layer,said barrier layer being formed on the exposed parts, i.e. the uncoveredparts, of a fluorine-containing dielectric. This barrier layer shouldadhere well on said fluorine-containing dielectric. This barrier layershould also neither corrode nor reveal a deterioration of itscharacteristics by the exposure to fluorine. Furthermore, this barrierlayer also has to form at least a diffusion barrier for fluorine inorder to inhibit the corrosion of other parts of the metallizationstructure. Preferably this barrier layer should also form a diffusionbarrier layer for Cu.

In an embodiment of the invention, a metallization structure isdisclosed comprising a barrier layer, said layer comprising a near noblemetal. Preferably the near noble metal Co is used. Co is much lessreactive than the refractory metals. Co adheres well onfluorine-containing silicon oxide based materials andfluorine-containing polymers. The fluorides of Co are stable andnon-volatile, i.e. contrary to e.g. Ti. A further advantage of Co isthat it can be selectively deposited using an electroless platingtechnique. It has been revealed (see also FIG. 2) that Co reacts readilywith fluorine thereby forming an in-situ cobalt-fluoride layer, i.e. alayer of Co_(x)F_(y), x and y being positive numbers. The growth of thiscobalt-fluoride layer is a self limiting reaction yielding a maximumthickness of about 5 nm. This reaction can occur spontaneously (20)dependent on the deposition technique used for the deposition of Co orstimulated by applying a heat treatment (21). Consequently, contrary toe.g. Ti which is permeable for fluorine, by the reaction of Co with afluorine-containing dielectric a diffusion barrier is formed inhibitingthe out-diffusion of fluorine from said fluorine-containing dielectricand thereby avoiding exposure of other parts of the metallizationstructure to fluorine. Furthermore, in contact with a silicon substrateCo can form a silicide-cobalt having a low resistivity and a low contactresistance to a silicon substrate. For the purposes of this disclosure,a silicide-cobalt is defined as Co_(x)Si_(y), x and y being positivenumbers.

Besides a barrier layer, preferably comprising a near noble metal,particularly Co, said metallization structure can further comprise aconductive pattern, for instance a conductive line or a set ofconductive lines. Preferably, said conductive pattern is composed of Cuor a Cu alloy. Cu is an interesting material due to its low resistivity.Furthermore, from the binary phase diagrams, it is known that Co doesnot form intermetallic compounds with Cu. Using Cu can also have somedisadvantages. A first possible disadvantage is that Cu easily corrodeswhen being exposed to fluorine. However, this corrosion is inhibited bythe in-situ formed barrier layer of a fluoride of cobalt which inhibitsthe out-diffusion of fluorine. A second possible disadvantage can be themigration of Cu in the surrounding materials resulting in adeterioration of the electrical and mechanical characteristics of thesematerials. However the in-situ formed barrier layer of cobalt-fluorideis also a diffusion barrier for Cu. Therefore said barrier layer can beused to encapsulate the Cu.

In another embodiment of the invention, as an example, a metallizationstructure and a method for fabricating this particular metallizationstructure, i.e. a dual damascene structure, is proposed (see FIG. 1). Itshould be clear however that the invention is not limited to thisparticular structure but the present invention can be applied for anymetallization structure comprising a fluorine-containing dielectric.Metallization structures are structures used to connect and interconnectactive and/or passive devices. These structures can comprise multiplemetal levels which are, dependent on the desired connection pattern,either separated one from another by means of interlevel or intralevelfluorine-containing dielectric layers or connected one to the other bymeans of a conductive connection through the fluorine-containingdielectric layer(s). These fluorine-containing layers can compriseopenings such as via holes, trenches or contact openings.

EXAMPLE

On a flattened substrate, i.e. a silicon wafer (1), a firstfluorine-containing dielectric layer (2) is formed. Thisfluorine-containing dielectric can be a polymer like or ceramic likedielectric, e.g. a fluorinated silicon oxide. Alternatively thisfluorine-containing dielectric can also be a dielectric where thefluorine is introduced only after the deposition, for instance by plasmafluorination. This holds for organic polymers comprising Phenyl groups.Examples of such polymers are the benzocyclobutarenes, i.e.benzocyclobutene (BCB) commercially available as Cyclotene 5021™, polyarylene ether, i.e FLARE™ II, aromatic hydrocarbon, i.e. SILK™,polyimides. An advantage of introducing fluorine after the deposition isthat this fluorination can be performed locally.

A hard mask layer (3), e.g. a silicon nitride layer, is formed on thefirst fluorine-containing dielectric layer. A hard mask layer is definedas a layer which can be etched selective to the underlying dielectriclayer. A lithographic resist layer (4) is deposited and patterned (stepa)). The hard mask layer is patterned (step b)) with a RIE (reactive ionetch) step using the patterned lithographic developed resist (4) as amask thereby creating at least one hole where the surface of the firstfluorine-containing dielectric layer is exposed. After the RIE step theresist left-over is removed.

A second fluorine-containing dielectric layer (5) is formed (step c))over the patterned hard mask layer and a resist layer (6) is formed onthis second fluorine-containing dielectric layer. The resist layer ispatterned (step d)) and the second fluorine-containing dielectric layeris etched using the patterned resist layer as a mask which can result inthe formation of a trench. The hard mask layer functions as an etch stoplayer thereby preventing the extension from the trench in the firstfluorine-containing dielectric layer (step e)). The first dielectriclayer is then etched using the patterned hard mask layer as a mask toform a contact to the substrate, i.e. exposing the surface of thesubstrate (step e)). The etching of the first and second dielectriclayer can be performed using a single etch step or two etch steps. Thepatterned resist layer is removed.

A thin layer (7) of a near noble metal, preferably Co, is formed (stepf)) over the exposed parts of the hard mask layer and the first andsecond fluorine-containing dielectric layer. By the reaction of Co andF, said F being supplied by said dielectric layer, a cobalt-fluoridelayer, i.e. a layer of Co_(x)F_(y), x and y being positive numbers, isformed at the interface between said dielectric layer and said Co layerto thereby form a diffusion barrier for said fluorine. This reaction canbe stimulated by a heating step. However the growth of thecobalt-fluoride layer is a self-limiting process yielding a maximumthickness of 5 nm. At the contact area to the substrate, i.e. at theinterface between the substrate and the Co layer, a fluorinatedcobaltsilicide is formed with a low contact resistance. So as explainedbefore, in fact a contact barrier layer is formed.

A conductive layer (8), preferably a Cu layer, is deposited. The Culayer fills the contact in the first and second dielectric layer and thetrench in the second dielectric layer.

The conductive layer is planarized (step g)) to electrically isolate thetrenches or contacts one from another. This planarization can beperformed using chemical mechanical polishing (CMP). The Cu is almostcompletely encapsulated by the Co inhibiting the out-diffusion of theCu, only at the topside the Cu is still uncovered.

In order to completely encapsulate the Cu, a second layer of Co (9) canbe deposited selectively (step h)) on the Cu. Subsequent deposition of athird fluorine-containing dielectric (or exposure to fluorine) will leadto a similar formation of a cobalt-fluoride layer on said second Colayer and completely encapsulate the Cu.

Co is typically a metal that allows deposition by electroless plating.If an adequate activation is performed, Cu as well as Co can bedeposited using plating deposition. Consequently the completemetallization sequence as described in the example but not limitedhereto can be carried out using plating deposition without the need forphysical vapour deposition (PVD).

In an embodiment of the invention, a method for fabricating ametallization structure is disclosed comprising the steps of:

depositing a first thin Co layer, or a layer of another near noble metallike e.g. Ni, Pd and Pt, on a first fluorine-containing dielectriclayer, said deposition leading to the reaction of Co and F, said F beingsupplied by said first dielectric layer, to thereby grow acobalt-fluoride layer at the interface between said first dielectriclayer and said first Co layer;

depositing Cu, or another metal like e.g. Al or an Al alloy, on saidfirst Co layer;

depositing a second Co layer selectively on the Cu

exposing said second Co layer to fluorine, e.g. by depositing a secondfluorine-containing dielectric on said second Co layer, leading to theformation of a cobalt-fluoride layer on said Co.

In a further embodiment of the invention, a metallization structure isfabricated by first depositing a Co layer, with a thickness typicallybetween 80 nm and 200 nm, or a layer of another near noble metal likee.g. Ni, Pd and Pt, on a fluorine-containing dielectric layer.Preferably this fluorine-containing dielectric comprises at least oneopening as e.g. a via hole or a trench. This deposition can e.g. be doneusing a physical vapor deposition technique and such that a barrierlayer is formed at least in these openings. This deposition leads to thereaction of Co and F, said F being supplied by said dielectric layer, tothereby grow a layer of a fluoride of said Co at the interface betweensaid dielectric layer and said first Co layer. This reaction can bestimulated by applying a heating step. Anyhow, as this reaction isself-limiting the thickness of the layer of said fluoride is typicallybetween 3 and 5 nm. This fluoride layer forms a diffusion barrier layerwhich is both impermeable for fluorine and Cu. Particularly, thereafterthe Co layer on this fluoride layer can be removed selectively to theunderlying fluoride layer by an electrochemical etch. Thereafter aCu-containing metal can be deposited on the fluoride layer, preferablyby means of electroplating, to thereby at least completely fill theseopenings.

What is claimed is:
 1. A metallization structure comprising: aconductive pattern; a fluorine-containing dielectric; and a barrierlayer comprising at least a first part, being positioned between saidfluorine-containing dielectric and said conductive pattern, said firstpart comprising a first sub-layer of a conductive material and a secondsub-layer of a fluoride of said conductive material adjacent to saidfluorine-containing dielectric, wherein said second sub-layer inhibitsout-diffusion of fluorine from said fluorine-containing dielectric. 2.The structure as recited in claim 1, wherein said barrier layercompletely encapsulates said fluorine-containing dielectric.
 3. Thestructure as recited in claim 1, wherein said barrier layer completelyencapsulates said conductive pattern.
 4. The structure as recited inclaim 1, where said conductive pattern is composed of at least one metalselected from the group consisting of Al, Cu, an Al-alloy and aCu-alloy.
 5. The structure as recited in claim 1, where said conductivematerial is a metal selected from the group consisting of Co, Ni, Pt andPd.
 6. The structure as recited in claim 1, wherein saidfluorine-containing dielectric comprises at least one opening.
 7. Thestructure as recited in claim 6, wherein said opening is a via hole or atrench.
 8. The structure as recited in claim 1, where said conductivepattern is composed of Cu or a Cu-alloy.
 9. The structure as recited inclaim 8, further comprising a Cu-barrier layer, being impermeable forcopper and positioned between said conductive pattern and said barrierlayer.
 10. The structure as recited in claim 9, where said Cu-barrierlayer is a Ta layer or a compound thereof.
 11. The structure a recitedin claim 1, wherein said barrier layer further comprises a second part,being positioned between a silicon layer and said conductive patternsaid second part consisting of a third sub-layer of said conductivematerial and a fourth sub-layer of a silicide of said conductivematerial, said fourth sub-layer contacting said silicon layer.
 12. Thestructure as recited in claim 11, where said silicon layer is at least apart of a silicon wafer.
 13. A method for fabricating a metallizationstructure on a substrate comprising the steps of: depositing a layer ofa conductive material on at least one exposed surface of afluorine-containing dielectric formed on said substrate; allowing thereaction between said layer of said conductive material and saidfluorine-containing dielectric to thereby form a layer of a fluoride ofsaid conductive material at the interface between said layer of saidconductive material and said fluorine-containing dielectric, whereinsaid layer of said fluoride of said conductive material inhibitsout-diffusion of fluorine from said fluorine-containing dielectric; anddepositing at least one metal on said layer of said conductive material.14. The method as recited in claim 13, wherein said metal is selectedfrom the group consisting of Al, Cu, an Al-alloy and a Cu-alloy.
 15. Themethod as recited in claim 13, wherein said conductive material is ametal selected from the group consisting of Co, Ni, Pt and Pd.
 16. Themethod as recited in claim 13, wherein prior to the deposition of saidmetal a Cu-barrier layer is formed at least on said layer of saidconductive material.
 17. The method as recited in claim 16, wherein saidCu-barrier layer is a layer comprising Ta or a compound thereof.
 18. Themethod as recited in claim 13, wherein said reaction is stimulated byheating said substrate.
 19. The method as recited in claim 14, whereinsaid heating is performed at a temperature in the range from 50 degreesC. to 500 degrees C.
 20. The method as recited in claim 14, wherein saidheating is performed at a temperature in the range from 50 degrees C. to350 degrees C.
 21. The method as recited in claim 14, wherein saidheating is performed at a temperature in the range from 50 degrees C. to300 degrees C.